Fault reporting tag for mesh access points

ABSTRACT

Mesh access point fault reporting. In particular implementations, a method includes receiving a fault indication indicating one or more failures; collecting fault data related to the one or more failures or a state of the mesh access point; and passing the fault data to the RFID tag, which wirelessly transmits messages relating to the fault.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.11/689,167 filed Mar. 21, 2007 and entitled “Fault Reporting Tag forMesh Access Points”.

TECHNICAL FIELD

This disclosure relates generally to wireless mesh networks.

BACKGROUND

Market adoption of wireless LAN (WLAN) technology has exploded, as usersfrom a wide range of backgrounds and vertical industries have broughtthis technology into their homes, offices, and increasingly into thepublic air space. This inflection point has highlighted not only thelimitations of earlier-generation systems, but also the changing rolethat WLAN technology now plays in people's work and lifestyles acrossthe globe. Indeed, WLANs are rapidly changing from convenience networksto business-critical networks. Increasingly users are depending on WLANsto improve the timeliness and productivity of their communications andapplications, and in doing so, require greater visibility, security,management, and performance from their network.

Managing mesh access points can be particularly challenging due to theremote distribution of the mesh access points. It is typically verycostly to debug problems associated with a given mesh access point if itbecomes isolated from a given network, especially if the problems mayhave occurred on the mesh access point and an administrator needs totravel physically to the remote site to troubleshoot the problems.Typically, if a mesh access point that experiences problems isidentified and located, the administrator may use a serial interface orother alternate interface at the mesh access point to troubleshoot theproblems if the administrator has physical access to the device.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example topological diagram of a hierarchicalwireless mesh network.

FIG. 2 illustrates an example hardware system, which may be used toimplement a mesh access point.

FIG. 3 illustrates an example hardware system, which may be used toimplement a radio frequency identification (RFID) tag.

FIG. 4 illustrates an example method implemented at a mesh access point.

FIG. 5 illustrates an example method implemented at an RFID tag inaccordance with one implementation.

FIG. 6 illustrates an example method implemented at an RFID tag inaccordance with another implementation.

DESCRIPTION OF EXAMPLE EMBODIMENTS A. Overview

Particular implementations facilitate fault reporting in wireless meshnetworks. According to one implementation, a mesh access point includesan RFID tag that provides for out-of-band reporting of faults when themesh access point itself may not be able to communicate over thewireless network. As described in more detail below, the mesh accesspoint includes a mesh access point module that interacts with the RFIDtag. For example, the mesh access point module passes identification andconfiguration information to the RFID tag when the mesh access pointinitializes and when the mesh access point detects errors (e.g.,connectivity problems) while operating in an access point mode in awireless mesh network. In one implementation, the mesh access pointmodule is operable to pass state information to the RFID tag, andpotentially other information, that may be useful for trouble shooting.In one implementation, if the mesh access point experiences a powerfailure, the RFID tag may detect the power failure and may generate afault report based on any information that the RFID tag may havecollected up until the power failure. As such, the RFID tag may generatea fault report based on identification information, configurationinformation, and other information provided to it, and broadcast faultreport messages that may be received by other nodes of the wireless meshnetwork and forwarded to a controller or network management server.

B. Example Wireless Mesh Network System Architecture

B.1. Network Topology

FIG. 1 illustrates a wireless mesh network according to oneimplementation of the present invention. In one implementation, thewireless mesh network includes a wireless mesh controller 20, a rootaccess point 21, and a plurality of child wireless mesh access points.In one implementation, the mesh access points are logically arranged ina hierarchy for purposes of routing traffic to the root access point(RAP), and on to a network. In one implementation, this hierarchy can bedynamically configured and shifted based on discovery of wirelessmanagement messages between wireless mesh access points, or staticallyconfigured.

In one implementation, a hierarchical architectural overlay is imposedon the mesh network of routing nodes to create a downstream directiontowards leaf routing nodes 35, and an upstream direction toward the rootaccess point 21. For example, in the hierarchical mesh networkillustrated in FIG. 1, first hop mesh access point 31 is the parent ofintermediate mesh access point 33. In addition, intermediate mesh accesspoints 33 and 34 are the parent to leaf mesh access point 35. In oneimplementation, this hierarchical relationship is used in routingpackets between wireless clients 60, or between wireless clients 60 andnetwork 30. Of course, a variety of wireless mesh network configurationsare possible, including non-hierarchical configurations, andhierarchical configurations with fewer or greater number of hierarchicaltree structures.

The mesh access points in the mesh network, in one implementation,generally include one radio, operating in a first frequency band, andassociated wireless communication functionality to communicate withother mesh access points to thereby implement the wireless backbone, asdiscussed more fully below. All or a subset of the mesh access points,in one implementation, also include an additional radio, operating in asecond, non-interfering frequency band, and other wireless communicationfunctionality to establish and maintain wireless connections with mobilestations, such as wireless client 60. For example, in 802.11 wirelessnetworks, the backbone radios on the wireless routing nodes may transmitwireless packets between each other using the 802.11a protocol on the 5GHz band, while the second radio on each mesh access point may interactwith wireless clients on the 2.4 GHz band (802.11b/g). Of course, thisrelation can also be reversed with backhaul traffic using the 802.11b/gfrequency band, and client traffic using the 802.11a band. In addition,the mesh access points may include only a single radio or additionalradios.

In one implementation, some wireless mesh networks can include acontroller and a plurality of mesh access points that are configuredinto one or more routing and control hierarchies based on automaticneighbor and route discovery protocols. In some environments, individualmesh access points automatically discover their neighbors and configurehierarchical routing configurations by selecting parent nodes based on avariety of factors. Mesh access points, in some systems, connect to awireless controller through one or more parents nodes in the routinghierarchy.

B.2. Wireless Mesh Access Point

FIG. 2 illustrates for didactic purposes a hardware system, which may beused to implement a wireless mesh access point in a wireless meshnetwork. In one implementation, the wireless mesh access point 300comprises a processor 308, a read-only memory (ROM) 309, and anelectronically erasable read-only memory (EEPROM) 310. The wireless meshaccess point 300 may also include one or more of the following: a memory312, a network interface 314 (e.g., an 802.3 interface) forcommunication with a LAN, a cache 316 for storing WLAN information, anda persistent memory 318. The wireless mesh access point 300 may alsoinclude a backhaul wireless network interface 320 having an antenna 321.Backhaul wireless network interface 320 is configured to transmit andreceive messages to/from one or more other wireless mesh access pointsin a mesh network. The wireless mesh access point 300 may also include aclient wireless network interface 322 (e.g., an IEEE 802.11 WLANinterface) having an antenna 323. Client wireless network interface 322is configured for wireless communication with one or more wirelessclients 60. The backhaul wireless network interface 320 and clientwireless network interface 322 may be radio interfaces. The wirelessmesh access point 300 may also include input/output (I/O) ports 324 anda system bus 326 interconnecting these components. As FIG. 2 alsoillustrates, mesh access point also includes a RFID tag 330. In oneimplementation, RFID tag 330 is operably connected to system bus 326using any suitable interface (e.g., a RS-232 serial interface, pulsecode modulation interface (PCMI), FireWire interface, universal serialbus (USB) interface).

In some implementations, wireless mesh access point use one or more ofthe following standards: WiFi/802.11, WiMax/802.16, 2G, 3G, or 4GWireless, Bluetooth/802.15, Zigbee, or any other suitable wirelesscommunication standards. In one implementation, wireless mesh accesspoint may have a separate access radio, and associated interfacecomponents, for communicating with a wireless client or other portablecomputer. The wireless mesh access points may also include softwaremodules, including Dynamic Host Configuration Protocol (DHCP) clients,transparent bridging, Lightweight Access Point Protocol (LWAPP), Cisco®Discovery Protocol (CDP) modules, wireless access point modules, SimpleNetwork Management Protocol (SNMP) functionality, etc., and devicedrivers (e.g., network and WLAN interface drivers) stored in persistentmemory 318 (e.g., a hard disk drive, flash memory, EEPROM, etc.). Atstart up, one or more of these software components are loaded intosystem memory 312 and then accessed and executed by processor 310. Inone implementation, the wireless mesh access point 300 includes softwareor firmware modules for recognizing the reception of network managementinformation and for storing such information in memory (e.g., EEPROM310). In a particular implementation, a mesh access point module is afirmware or software module including computer-readable instructionsoperative to cause the processor and other components to perform thefunctions described herein. In the implementations described herein, themesh access point module is also operative to communicate with RFIDmodule 330 to pass fault report data, commands, and/or heartbeatmessages over system bus 326.

B.3. RFID Tag

FIG. 3 illustrates an example hardware system, which may be used toimplement an RFID tag 330 of FIG. 1. In one embodiment, the RFID tag 330includes an interface 332 for communicating on the system bus of themesh access point, a battery 334 or other external power source separatefrom the mesh access point, a wireless transceiver 336 with an antennae338, a processor 340, and a persistent memory 342 such as a flash memorycoupled to each other as shown. In one implementation, wirelesstransceiver 336 provides communication between hardware system 400 andany of a wide range of wireless networks, such as a WLAN (i.e., IEEE802.11), WiMax (i.e., IEEE 802.16), Cellular (e.g., GSMA), etc.Persistent memory 342 provides permanent storage for data andprogramming instructions to perform the above-described functionsimplemented by processor 340.

As described in more detail below, the RFID tag 330 storesidentification and configuration information associated with the meshaccess point 300 when the mesh access point initializes and when themesh access point detects errors (e.g., connectivity problems) whencommunicating with the wireless network. In one implementation, the RFIDtag 330 is operable to generate fault reports and broadcast fault reportmessages.

C. Communication Between the Mesh Access Point and the RFID Tag

As described in more detail below, the mesh access point module of themesh access point 300 may send identification and configurationinformation to the RFID tag 330 upon initialization. Furthermore, theRFID tag 330 may receive error log information from the mesh accesspoint module of mesh access point 300 during normal operation. Upondetection of a communication failure, or other critical error or failurecondition, by either the mesh access point 300 (when it has power or isotherwise able) or by the RFID tag 330, the RFID tag 330 may generate afault report including available identification, configuration and/orfault information and broadcast the fault report information in faultreport messages using wireless transceiver 336

In one implementation, during initialization/power-up of the mesh accesspoint 300, the mesh access point 300 discovers the RFID tag 330 andsends identification information (e.g., Media Access Control address,serial number, product types, model number, etc.) and configurationinformation (e.g., software version, operating parameters, etc.) to theRFID tag 330. The RFID tag 330 may then store the identification andconfiguration information to a persistent memory (e.g., flash memory).

Furthermore, the RFID tag 330, in some particular implementations, maybe triggered to transmit fault report messages in response to explicitcommands from mesh access point 300 or to detected failures of the meshaccess point 300.

C.1. Failure Detection by the Mesh Access Point

FIG. 4 illustrates an example method implemented at a mesh access point.The process begins when the mesh access point 300 detects a fault (402).In one implementation, the fault may relate to a communication problemwith a wireless network interface of mesh access point 300. The meshaccess point module collects fault data (404) and then logs the faultdata (406). In one implementation, the fault data may includeinformation describing the nature of the problem (e.g., no communicationat all, authentication failure, etc.). The mesh access point module thendetermines whether to apply out-of-band (OOB) management (408). In oneimplementation, this determination may be based on one or more policies.For example, if the fault data indicates that the performance of themesh access point 300 is degraded, but the mesh access point 300 canstill communicate with the wireless network, the mesh access pointmodule may apply in-band management and communicate directly over thewireless network. If the fault data indicates that the mesh access point300 cannot communicate with the wireless network, the mesh access pointmodule may utilize the RFID tag 330 to broadcast a fault report message.In some instances, however, the access point module may opt to transmitfault report data to the RFID tag 330 and attempt in-band communicationsusing wireless network interface 320 and/or 322. As such, if the meshaccess point module applies OOB management, the mesh access point modulepasses the fault data to the RFID tag 330 (410). The operations of theRFID tag 330 are described in more detail below in connection with FIGS.5 and 6. As FIG. 4 illustrates, the mesh access point module may alsoapply a trap policy (412). For example, the mesh access point module mayattempt to send an in-band notification to the wireless networkinfrastructure indicating any problems. Transmitting a trap (e.g., anSNMP trap) may be controlled by one or more policies.

C.2. RFID Process with Explicit Command Fault Reporting

The following example process can be implemented when the mesh accesspoint 300 loses communication with the wireless network due tocommunication errors or failures, but where the mesh access point 300still has power and its software or firmware modules are still capableof execution.

FIG. 5 illustrates an example method implemented at an RFID tag inaccordance with one particular implementation of the invention. As FIG.5 shows, the RFID tag 330 determines if it has received, from accesspoint module, a command including fault data (502). If the RFID tag 330received a command including fault data, the RFID tag 330 stores thefault data in persistent memory (504). The RFID tag 330 may optionallyquery one or more components of the mesh access point 300 to possiblygather additional information (506). Such information may include stateinformation, status information, or any other physical environment andparameter information (e.g., antenna orientation, device or componentstatus information, global positioning system (GPS) positioninformation, etc.) that may be useful for troubleshooting the meshaccess point 300.

The RFID tag 330 then enters a beacon phase (508). During the beaconphase the RFID tag 330, in one implementation, broadcasts 802.11multicast frames with one or more aspects of identification data,configuration data, or fault data. In one implementation, the RFID tag330 transmits the multicast frames on one to a plurality of frequencychannels preconfigured on the RFID tag 330. In one implementation, theRFID tag 330 may transmit the multicast frames on all availableoperating channels within a given band to better ensure that neighboringmesh access points (or other wireless nodes) detect the fault reportmessages. The transmitted fault report messages may be detected by oneor more neighboring mesh access points, which may be configured toautomatically forward received fault report messages to an appropriatewireless network infrastructure node (e.g., backhaul controller, networkmanagement system, etc.) for processing (e.g., notification andtroubleshooting).

In some implementations, the mesh access point 300 may have acertificate for mesh access point authentication, and may also send thecertificate to the RFID tag 330 upon initialization. As such, the RFIDtag 330 may include the certificate or information in the certificate todigitally sign, and/or encrypt, the fault report message to allow thefault message to be authenticated.

C.3. RFID Process Responsive to Access Point Failure

The following process is associated with scenarios where the mesh accesspoint 300 fails due to power loss, or a problem with software, firmwareand/or hardware. Because the RFID tag 330 is separately powered by abattery, the RFID tag 330 may still operate to detect a failure of themesh access point 300 due to power loss (or some other problem where themesh access point 300 is failing to respond over the internal hardwareinterface with the RFID tag 330). The RFID tag 330 can also performother functions as described below in connection with FIG. 6.

FIG. 6 illustrates an example method implemented at an RFID tag inaccordance with a particular implementation of the invention. In theimplementation described below, RFID tag 330 uses heartbeat messages todetect the operational presence of the access point 300. That is, in oneimplementation, the access point module is configured to transmitmessages to RFID tag 330 on a periodic basis. In other implementations,the RFID tag 330 is operative to transmit messages to access pointmodule, which responds to the messages. A failure to detect suchheartbeat messages may cause RFID tag to enter a beacon phase andtransmit fault reporting messages.

In a particular implementation, as FIG. 6 shows, the RFID tag 330determines if an expected heartbeat message from mesh access pointmodule has timed out (602). In one implementation, the RFID tag 330wakes up periodically to sense whether the mesh access point module ofmesh access point 300 is still operational. For example, in oneimplementation, RFID tag 330 may wake up and transmit a keep-alivemessage to mesh access point module. If a response times out, the RFIDtag 330 optionally determines whether the mesh access point 300 isre-booting (604). In one implementation, the mesh access point module isconfigured to notify RFID tag 330 any time it re-boots. If so, the RFIDtag 330 determines if a reboot time has expired (606). If the reboottime has expired, the RFID tag 330 then generates a fault report (608).The RFID tag 330 then enters a beacon phase (610). In oneimplementation, the beacon phase is similar to the beacon phasedescribed above in FIG. 5, where the RFID tag 330 broadcasts 802.11multicast frames including fault report data including one or moreaspects of identification data, configuration data, and fault data.

After the appropriate wireless network infrastructure node (e.g.,backhaul controller, network management system, etc.) receives the faultreport, the wireless network infrastructure node may perform one or moreoperations, such as notifying a network administrator and/or attemptingto transmit messages to the RFID tag 330. For example, in oneimplementation, a network management server may communicate with theRFID tag 330 to attempt one or more troubleshooting operations. In oneimplementation, if appropriate, the network management server maydetermine that the mesh access point 300 requires new securityinformation, and may attempt to reconfigure the mesh access point 300(e.g., change particular security settings) by communicating one or moresecurity settings through the RFID tag 330 to the mesh access point 300.In some implementations, the network management server may notify anappropriate network administrator and include one or more attributes ofthe fault report message.

The present invention has been explained with reference to specificembodiments. For example, while embodiments of the present inventionhave been described as operating in connection with IEEE 802.11networks, the present invention can be used in connection with anysuitable wireless network environment. Other embodiments will be evidentto those of ordinary skill in the art. It is therefore not intended thatthe present invention be limited, except as indicated by the appendedclaims.

What is claimed is:
 1. An access point comprising: one or moreprocessors; a memory; a wireless network interface; a radio-frequencyidentification (RFID) tag; and an access point module, physically storedin the memory, comprising instructions operative to cause the one ormore processors to: receive a fault indication indicating one or morefailures; collect fault data related to the one or more failures or astate of the access point; and pass the fault data to the RFID tag;wherein the RFID tag is operative to: autonomously detect a failure ofthe access point module or the access point; and automatically inresponse to the detected failure, wirelessly broadcast one or more faultreport messages on one or more radio frequency channels.
 2. An accesspoint comprising: one or more processors; a memory; a wireless networkinterface; a radio-frequency identification (RFID) tag; and an accesspoint module, physically stored in the memory, comprising instructionsoperative to cause the one or more processors to: receive a faultindication indicating one or more failures; collect fault data relatedto the one or more failures or a state of the access point; and pass thefault data to the RFID tag; wherein the RFID tag is operative to: detecta failure of the access point module or the access point; andautomatically in response to the detected failure, wirelessly broadcastone or more fault report messages on one or more radio frequencychannels; wherein the access point module further comprises instructionsoperative to cause the one or more processors to: determine, in responseto the fault indication, whether the access point can communicate with awireless network, transmit an in-band fault reporting message over thewireless network via the wireless network interface, if the access pointcan communicate with the wireless network; utilize the RFID tag, if theaccess point can not communicate with the wireless network.
 3. Theaccess point of claim 2 wherein the in-band fault reporting message is aSimple Network Management Protocol (SNMP) trap.
 4. The access point ofclaim 1 wherein the one or more fault report messages transmitted by theRFID tag are transmitted as multicast frames.
 5. The access point ofclaim 1 wherein the access point module further comprises instructionsoperative to cause the one or more processors to: forward faultreporting messages received from RFID tags of other access points to awireless network management node for processing.
 6. The access point ofclaim 1 wherein the RFID tag is operative to digitally sign the one ormore fault reporting messages with a digital certificate of the accesspoint.
 7. The access point of claim 1 wherein the RFID tag is operativeto encrypt the one or more fault reporting messages.
 8. The access pointof claim 1 wherein the access point module is operative to passconfiguration information to the RFID tag.
 9. The access point of claim1 wherein the access point module is operative to pass identificationinformation to the RFID tag.
 10. The access point of claim 1 wherein thefault report messages comprises one or more aspects of identificationdata, configuration data, and fault data.
 11. The access point of claim1 wherein the RFID tag is operative to store the fault data in apersistent memory.
 12. The access point of claim 1 wherein the RFID tagis operative to query one or more components of the wireless accesspoint for state information.
 13. A method comprising: detecting, at anaccess point, a fault indication indicating one or more failures on theaccess point; collecting, by the access point, fault data related to theone or more failures or a state of the access point; and passing thefault data to an RFID tag connected to the access point; wherein theRFID tag is operative to: autonomously detect a failure of the accesspoint; and automatically in response to the detected failure, wirelesslybroadcast one or more fault report messages on one or more radiofrequency channels.
 14. A method comprising: detecting, at an accesspoint, a fault indication indicating one or more failures on the accesspoint; collecting, by the access point, fault data related to the one ormore failures or a state of the access point; passing the fault data toan RFID tag connected to the access point; wherein the RFID tag isoperative to: detect a failure of the access point; and automatically inresponse to the detected failure, wirelessly broadcast one or more faultreport messages on one or more radio frequency channels; and determiningby the access point, in response to the fault indication, whether theaccess point can communicate with a wireless network, transmitting anin-band fault reporting message over the wireless network via a wirelessnetwork interface of the access point, if the access point cancommunicate with the wireless network; and utilizing by the access pointthe RFID tag, if the access point can not communicate with the wirelessnetwork.
 15. The method of claim 13 further comprising forwarding, bythe access point, fault reporting messages received from RFID tags ofother access points to a wireless network management node forprocessing.
 16. The method of claim 13 further comprising digitallysigning, by the RFID tag, the one or more fault reporting messages witha digital certificate of the access point.
 17. The method of claim 13further comprising, storing, by the RFID tag, the fault data in apersistent memory.
 18. The method of claim 13 further comprising,querying, by the RFID tag one or more components of the wireless accesspoint for state information.
 19. The method of claim 13 wherein the oneor more fault report messages transmitted by the RFID tag aretransmitted as multicast frames.
 20. The method of claim 13 furthercomprising passing identification information of the access point fromthe access point to the RFID tag.